Geologic
Time Table

The development of
life on Earth

This extensive time
table follows the development of Earth from the moment of the Big Bang
until today. Where the geometry of Earth was known, also world maps are
shown.

To follow the history of
the Earth and its life forms, start at the bottom of the last table. For
successful printing, set the left and right margins in your page
settings to minimal, e.g left 0.5 cm (0.2").Information from various
sources. Maps adapted from Stephen Jay Gould The Book of Life, 1993.

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Cenozoic
- Quaternary

Holocene10kya till present

AD
1350-1800 Little Ice Age. since then a warming trend. Major
habitat changes and deforestations caused by humans. A major extinction
wave due to introduced pests and habitat destruction.

The
last major ice age ends and the sea level rises by 80-110m worldwide, causing
new continental margins, dunes and beaches. Climate still fluctuates in
ten little ice ages. Humans spread across
America and all islands. Major extinctions of large animals and birds due
to humans.

Pleistocene1.6-0.01 Mya

Climate
fluctuating cold to mild . The era of ice ages. Numerous glacial
advances and retreats; fiords formed. Uplift of the Sierra Nevada; deserts
on large scale; Sahara formed. Ten major ice ages of 100ky each between
1Mya and 100kya. Last ice age from 100kya to 10kya.Planetary
spread of Homo Sapiens over Eurasia; extinction of many species due to
the ice ages; extinction of many large mammals and birds due to humans.

Cenozoic
- Tertiary66.4-1.6 Mya

Pliocene5-2 Mya

Cooler
climate; continued uplift and mountain building, with widespread glaciation
in Northern Hemisphere. Uplift of Panama joins North and South America.Large
carnivores. First known appearance of hominids (humanlike primates)

Mild
to very tropical climate. Many lakes in western North America. Australia
separates from Antarctica; India collides with Asia.Primitive
horses, tiny camels, marsupials; modern and giant types of bird. Most groups
now well formed; barnacles, oysters, cuttlefish, crabs, sponges, freshwater
snails. Formation of grasslands.

Tropical
to subtropical climate. Elevation of Rocky Mountains at end of period.
Africa and South America separate. In warm, shallow seas, vast layers of
chalk laid down by marine organisms.
Birds well developed. Marsupials, insectivores and flowering plants become
abundant. At end of period extinction of dinosaurs, belemnites, ammonites
and most cycads. Fish survived, mammals and some reptiles. Angiosperms
dominate the land flora, colonise most land and diversify.

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Jurassic208-144 Mya

Mild
climate. Continents low, with large areas covered by seas. Mountains rise
from Alaska to Mexico.Dinosaurs' zenith.
Flying reptiles, small mammals and birds appear. Many ammonites and other
mollusks dominate the sea. Gymnosperms, especially cycads and ferns. First
flowering plants (angiosperms).

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208 Mya

Mass extinctions

Triassic245-208 Mya

At
first, deserts stretched out over most of the land, slowly giving way to
a mild, moist climate with great areas of forested plains. Continents mountainous
and joined in one mass. Large areas arid. Eruptions in eastern North America.
Appalachians uplifted and broken into basins. The
age of dinosaurs, on land, in the sea and in between. Amphibians in fresh
water, retreating. Primitive mammals appear. Forests of gymnosperms and
ferns.

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248 Mya

Mass extinctions

Paleozoic540-245 Mya

Permian286-245 Mya

Extremely
violent climate changes: deserts, swamps, ice. Extensive glaciation in
Southern Hemisphere. Seas drain from land; worldwide aridity. Urals formed.
Appalachians formed by end of Paleozoic. Large
amphibians. Reptiles diversify. Bugs and beetles (metamorphosis). Age of
the seed plants. Origin of conifers, cycads and ginkgos; possible origin
of flowering plants; earlier forest types wane. At end of period extinctions
of many groups: trilobites, eurypterids, many kinds of corals, bryozoa,
sea lilies, brachiopods. Early fishes (placoderms) and many kinds of shark
disappeared.

Violent
change in the Earth's landscape by volcanic activity and crustal movements,
folding and mountain forming. Europe mountainous with arid basins. Mountains
and volcanoes in eastern US and Canada. Rest of north America low and flat.
Sea covers most of land. Climate became drier. Age
of fishes. Sharks, rays. Fishes move into the open seas. Lunged fishes
(paddle-fins). Amphibians appear. Mollusks abundant. Extinction of
primitive vascular plants. Origin of modern groups of vascular plants with
true leaves, roots and stems (liverworts). The Earth started to look green.
Some plants started to produce seeds, rather than spores.

Planet forms from accumulation
of cosmic dust and from meteorite impacts. These impacts and the heat caused
by compression, melt the interior of the planet. The heat melts the Earth's
interior to enable heavy elements to migrate to its centre, while light
elements migrate to its crust. 4400 Mya the liquid core with the mantle
appeared. Planet cools. Formation of Earth's crust (4200 Mya). Extensive
volcanic activity prevents life from forming.

.

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Formation
of universe15 - 4.5 Gya

sun's planets4560 Mya

.

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sun and solar system5000 Mya

Universe is 2/3 its present
size. From a left-over dust cloud originating from a supernova explosion,
the sun forms, attracting most of the material. But rotational momentum
has kept enough debris in space to form the planets. The sun's interior
heats to 15 million degrees, hot enough for nuclear fusion: protons fuse
into helium

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Unknown period

The exact age of the universe
is not known (15 to 9 Gya). Below this line, all time is relative to the
Big Bang; above it, time is relative to the present.

first galaxies1000 My

Universe has expanded to
1/5 its present size. Nuclear reactions inside stars (supernovas) have
made most of the heavy elements from which terrestrial planets are made
and the elements necessary for life. The Milky Way, our glaxy, was formed
10,000 Mya. The universe cools further to 3ºK, its temperature today.

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Universe becomes transparent
300,000 y

Matter clusters into ever
larger units. Stars are formed. The universe becomes transparent. Its radiation,
the backround radiation, is still observable today.

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The hot universeMatter/radiation soup0 - 0.01 s

Formation of nucleotides10-5 to 10-2
s

All forms of particles are
formed: neutrons, protons, electrons, etc. The universe expands to 1/1000
present size, temperature cools to 3000ºK. The light elements hydrogen
and helium are formed.

.

Moment of inflation 10-12
-

The universe has cooled
to 1015 degrees, being a soup of matter (quarks) and radiation,
a dense plasma gas under very high pressure. As the universe continues
to expand, it cools further and matter wins over antimatter. The universe
inflates rapidly to almost 1/1000 present size.

.

Moment of infinite temperature 0-10-12
s

The very moment of the big
bang is shrouded in mystery because scientists believe that conventional
physics won't apply at the very high temperatures in excess of a million
billon degrees 1015ºC.
Electromagnetic radiation and matter are indistinguishable.

Geologists use a finer division
of eras, periods, epochs and ages as shown below. Note that the starting
and ending ages have some uncertainty, increasing towards earlier times.
A typical error of 0.2 to 1% should be expected.